1 /* 2 * Generic PPP layer for Linux. 3 * 4 * Copyright 1999-2002 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * The generic PPP layer handles the PPP network interfaces, the 12 * /dev/ppp device, packet and VJ compression, and multilink. 13 * It talks to PPP `channels' via the interface defined in 14 * include/linux/ppp_channel.h. Channels provide the basic means for 15 * sending and receiving PPP frames on some kind of communications 16 * channel. 17 * 18 * Part of the code in this driver was inspired by the old async-only 19 * PPP driver, written by Michael Callahan and Al Longyear, and 20 * subsequently hacked by Paul Mackerras. 21 * 22 * ==FILEVERSION 20041108== 23 */ 24 25 #include <linux/module.h> 26 #include <linux/kernel.h> 27 #include <linux/kmod.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/idr.h> 31 #include <linux/netdevice.h> 32 #include <linux/poll.h> 33 #include <linux/ppp_defs.h> 34 #include <linux/filter.h> 35 #include <linux/ppp-ioctl.h> 36 #include <linux/ppp_channel.h> 37 #include <linux/ppp-comp.h> 38 #include <linux/skbuff.h> 39 #include <linux/rtnetlink.h> 40 #include <linux/if_arp.h> 41 #include <linux/ip.h> 42 #include <linux/tcp.h> 43 #include <linux/spinlock.h> 44 #include <linux/rwsem.h> 45 #include <linux/stddef.h> 46 #include <linux/device.h> 47 #include <linux/mutex.h> 48 #include <linux/slab.h> 49 #include <linux/file.h> 50 #include <asm/unaligned.h> 51 #include <net/slhc_vj.h> 52 #include <linux/atomic.h> 53 54 #include <linux/nsproxy.h> 55 #include <net/net_namespace.h> 56 #include <net/netns/generic.h> 57 58 #define PPP_VERSION "2.4.2" 59 60 /* 61 * Network protocols we support. 62 */ 63 #define NP_IP 0 /* Internet Protocol V4 */ 64 #define NP_IPV6 1 /* Internet Protocol V6 */ 65 #define NP_IPX 2 /* IPX protocol */ 66 #define NP_AT 3 /* Appletalk protocol */ 67 #define NP_MPLS_UC 4 /* MPLS unicast */ 68 #define NP_MPLS_MC 5 /* MPLS multicast */ 69 #define NUM_NP 6 /* Number of NPs. */ 70 71 #define MPHDRLEN 6 /* multilink protocol header length */ 72 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 73 74 /* 75 * An instance of /dev/ppp can be associated with either a ppp 76 * interface unit or a ppp channel. In both cases, file->private_data 77 * points to one of these. 78 */ 79 struct ppp_file { 80 enum { 81 INTERFACE=1, CHANNEL 82 } kind; 83 struct sk_buff_head xq; /* pppd transmit queue */ 84 struct sk_buff_head rq; /* receive queue for pppd */ 85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 86 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ 87 int hdrlen; /* space to leave for headers */ 88 int index; /* interface unit / channel number */ 89 int dead; /* unit/channel has been shut down */ 90 }; 91 92 #define PF_TO_X(pf, X) container_of(pf, X, file) 93 94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 96 97 /* 98 * Data structure to hold primary network stats for which 99 * we want to use 64 bit storage. Other network stats 100 * are stored in dev->stats of the ppp strucute. 101 */ 102 struct ppp_link_stats { 103 u64 rx_packets; 104 u64 tx_packets; 105 u64 rx_bytes; 106 u64 tx_bytes; 107 }; 108 109 /* 110 * Data structure describing one ppp unit. 111 * A ppp unit corresponds to a ppp network interface device 112 * and represents a multilink bundle. 113 * It can have 0 or more ppp channels connected to it. 114 */ 115 struct ppp { 116 struct ppp_file file; /* stuff for read/write/poll 0 */ 117 struct file *owner; /* file that owns this unit 48 */ 118 struct list_head channels; /* list of attached channels 4c */ 119 int n_channels; /* how many channels are attached 54 */ 120 spinlock_t rlock; /* lock for receive side 58 */ 121 spinlock_t wlock; /* lock for transmit side 5c */ 122 int mru; /* max receive unit 60 */ 123 unsigned int flags; /* control bits 64 */ 124 unsigned int xstate; /* transmit state bits 68 */ 125 unsigned int rstate; /* receive state bits 6c */ 126 int debug; /* debug flags 70 */ 127 struct slcompress *vj; /* state for VJ header compression */ 128 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 129 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 130 struct compressor *xcomp; /* transmit packet compressor 8c */ 131 void *xc_state; /* its internal state 90 */ 132 struct compressor *rcomp; /* receive decompressor 94 */ 133 void *rc_state; /* its internal state 98 */ 134 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 135 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 136 struct net_device *dev; /* network interface device a4 */ 137 int closing; /* is device closing down? a8 */ 138 #ifdef CONFIG_PPP_MULTILINK 139 int nxchan; /* next channel to send something on */ 140 u32 nxseq; /* next sequence number to send */ 141 int mrru; /* MP: max reconst. receive unit */ 142 u32 nextseq; /* MP: seq no of next packet */ 143 u32 minseq; /* MP: min of most recent seqnos */ 144 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 145 #endif /* CONFIG_PPP_MULTILINK */ 146 #ifdef CONFIG_PPP_FILTER 147 struct bpf_prog *pass_filter; /* filter for packets to pass */ 148 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 149 #endif /* CONFIG_PPP_FILTER */ 150 struct net *ppp_net; /* the net we belong to */ 151 struct ppp_link_stats stats64; /* 64 bit network stats */ 152 }; 153 154 /* 155 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 156 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 157 * SC_MUST_COMP 158 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 159 * Bits in xstate: SC_COMP_RUN 160 */ 161 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 162 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 163 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 164 165 /* 166 * Private data structure for each channel. 167 * This includes the data structure used for multilink. 168 */ 169 struct channel { 170 struct ppp_file file; /* stuff for read/write/poll */ 171 struct list_head list; /* link in all/new_channels list */ 172 struct ppp_channel *chan; /* public channel data structure */ 173 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 174 spinlock_t downl; /* protects `chan', file.xq dequeue */ 175 struct ppp *ppp; /* ppp unit we're connected to */ 176 struct net *chan_net; /* the net channel belongs to */ 177 struct list_head clist; /* link in list of channels per unit */ 178 rwlock_t upl; /* protects `ppp' */ 179 #ifdef CONFIG_PPP_MULTILINK 180 u8 avail; /* flag used in multilink stuff */ 181 u8 had_frag; /* >= 1 fragments have been sent */ 182 u32 lastseq; /* MP: last sequence # received */ 183 int speed; /* speed of the corresponding ppp channel*/ 184 #endif /* CONFIG_PPP_MULTILINK */ 185 }; 186 187 struct ppp_config { 188 struct file *file; 189 s32 unit; 190 bool ifname_is_set; 191 }; 192 193 /* 194 * SMP locking issues: 195 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 196 * list and the ppp.n_channels field, you need to take both locks 197 * before you modify them. 198 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 199 * channel.downl. 200 */ 201 202 static DEFINE_MUTEX(ppp_mutex); 203 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 204 static atomic_t channel_count = ATOMIC_INIT(0); 205 206 /* per-net private data for this module */ 207 static int ppp_net_id __read_mostly; 208 struct ppp_net { 209 /* units to ppp mapping */ 210 struct idr units_idr; 211 212 /* 213 * all_ppp_mutex protects the units_idr mapping. 214 * It also ensures that finding a ppp unit in the units_idr 215 * map and updating its file.refcnt field is atomic. 216 */ 217 struct mutex all_ppp_mutex; 218 219 /* channels */ 220 struct list_head all_channels; 221 struct list_head new_channels; 222 int last_channel_index; 223 224 /* 225 * all_channels_lock protects all_channels and 226 * last_channel_index, and the atomicity of find 227 * a channel and updating its file.refcnt field. 228 */ 229 spinlock_t all_channels_lock; 230 }; 231 232 /* Get the PPP protocol number from a skb */ 233 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 234 235 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 236 #define PPP_MAX_RQLEN 32 237 238 /* 239 * Maximum number of multilink fragments queued up. 240 * This has to be large enough to cope with the maximum latency of 241 * the slowest channel relative to the others. Strictly it should 242 * depend on the number of channels and their characteristics. 243 */ 244 #define PPP_MP_MAX_QLEN 128 245 246 /* Multilink header bits. */ 247 #define B 0x80 /* this fragment begins a packet */ 248 #define E 0x40 /* this fragment ends a packet */ 249 250 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 251 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 252 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 253 254 /* Prototypes. */ 255 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 256 struct file *file, unsigned int cmd, unsigned long arg); 257 static void ppp_xmit_process(struct ppp *ppp); 258 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 259 static void ppp_push(struct ppp *ppp); 260 static void ppp_channel_push(struct channel *pch); 261 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263 static void ppp_receive_error(struct ppp *ppp); 264 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 265 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 266 struct sk_buff *skb); 267 #ifdef CONFIG_PPP_MULTILINK 268 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 269 struct channel *pch); 270 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 271 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 272 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 273 #endif /* CONFIG_PPP_MULTILINK */ 274 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 275 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 276 static void ppp_ccp_closed(struct ppp *ppp); 277 static struct compressor *find_compressor(int type); 278 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 279 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 280 static void init_ppp_file(struct ppp_file *pf, int kind); 281 static void ppp_destroy_interface(struct ppp *ppp); 282 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 283 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 284 static int ppp_connect_channel(struct channel *pch, int unit); 285 static int ppp_disconnect_channel(struct channel *pch); 286 static void ppp_destroy_channel(struct channel *pch); 287 static int unit_get(struct idr *p, void *ptr); 288 static int unit_set(struct idr *p, void *ptr, int n); 289 static void unit_put(struct idr *p, int n); 290 static void *unit_find(struct idr *p, int n); 291 static void ppp_setup(struct net_device *dev); 292 293 static const struct net_device_ops ppp_netdev_ops; 294 295 static struct class *ppp_class; 296 297 /* per net-namespace data */ 298 static inline struct ppp_net *ppp_pernet(struct net *net) 299 { 300 BUG_ON(!net); 301 302 return net_generic(net, ppp_net_id); 303 } 304 305 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 306 static inline int proto_to_npindex(int proto) 307 { 308 switch (proto) { 309 case PPP_IP: 310 return NP_IP; 311 case PPP_IPV6: 312 return NP_IPV6; 313 case PPP_IPX: 314 return NP_IPX; 315 case PPP_AT: 316 return NP_AT; 317 case PPP_MPLS_UC: 318 return NP_MPLS_UC; 319 case PPP_MPLS_MC: 320 return NP_MPLS_MC; 321 } 322 return -EINVAL; 323 } 324 325 /* Translates an NP index into a PPP protocol number */ 326 static const int npindex_to_proto[NUM_NP] = { 327 PPP_IP, 328 PPP_IPV6, 329 PPP_IPX, 330 PPP_AT, 331 PPP_MPLS_UC, 332 PPP_MPLS_MC, 333 }; 334 335 /* Translates an ethertype into an NP index */ 336 static inline int ethertype_to_npindex(int ethertype) 337 { 338 switch (ethertype) { 339 case ETH_P_IP: 340 return NP_IP; 341 case ETH_P_IPV6: 342 return NP_IPV6; 343 case ETH_P_IPX: 344 return NP_IPX; 345 case ETH_P_PPPTALK: 346 case ETH_P_ATALK: 347 return NP_AT; 348 case ETH_P_MPLS_UC: 349 return NP_MPLS_UC; 350 case ETH_P_MPLS_MC: 351 return NP_MPLS_MC; 352 } 353 return -1; 354 } 355 356 /* Translates an NP index into an ethertype */ 357 static const int npindex_to_ethertype[NUM_NP] = { 358 ETH_P_IP, 359 ETH_P_IPV6, 360 ETH_P_IPX, 361 ETH_P_PPPTALK, 362 ETH_P_MPLS_UC, 363 ETH_P_MPLS_MC, 364 }; 365 366 /* 367 * Locking shorthand. 368 */ 369 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 370 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 371 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 372 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 373 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 374 ppp_recv_lock(ppp); } while (0) 375 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 376 ppp_xmit_unlock(ppp); } while (0) 377 378 /* 379 * /dev/ppp device routines. 380 * The /dev/ppp device is used by pppd to control the ppp unit. 381 * It supports the read, write, ioctl and poll functions. 382 * Open instances of /dev/ppp can be in one of three states: 383 * unattached, attached to a ppp unit, or attached to a ppp channel. 384 */ 385 static int ppp_open(struct inode *inode, struct file *file) 386 { 387 /* 388 * This could (should?) be enforced by the permissions on /dev/ppp. 389 */ 390 if (!capable(CAP_NET_ADMIN)) 391 return -EPERM; 392 return 0; 393 } 394 395 static int ppp_release(struct inode *unused, struct file *file) 396 { 397 struct ppp_file *pf = file->private_data; 398 struct ppp *ppp; 399 400 if (pf) { 401 file->private_data = NULL; 402 if (pf->kind == INTERFACE) { 403 ppp = PF_TO_PPP(pf); 404 rtnl_lock(); 405 if (file == ppp->owner) 406 unregister_netdevice(ppp->dev); 407 rtnl_unlock(); 408 } 409 if (atomic_dec_and_test(&pf->refcnt)) { 410 switch (pf->kind) { 411 case INTERFACE: 412 ppp_destroy_interface(PF_TO_PPP(pf)); 413 break; 414 case CHANNEL: 415 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 416 break; 417 } 418 } 419 } 420 return 0; 421 } 422 423 static ssize_t ppp_read(struct file *file, char __user *buf, 424 size_t count, loff_t *ppos) 425 { 426 struct ppp_file *pf = file->private_data; 427 DECLARE_WAITQUEUE(wait, current); 428 ssize_t ret; 429 struct sk_buff *skb = NULL; 430 struct iovec iov; 431 struct iov_iter to; 432 433 ret = count; 434 435 if (!pf) 436 return -ENXIO; 437 add_wait_queue(&pf->rwait, &wait); 438 for (;;) { 439 set_current_state(TASK_INTERRUPTIBLE); 440 skb = skb_dequeue(&pf->rq); 441 if (skb) 442 break; 443 ret = 0; 444 if (pf->dead) 445 break; 446 if (pf->kind == INTERFACE) { 447 /* 448 * Return 0 (EOF) on an interface that has no 449 * channels connected, unless it is looping 450 * network traffic (demand mode). 451 */ 452 struct ppp *ppp = PF_TO_PPP(pf); 453 454 ppp_recv_lock(ppp); 455 if (ppp->n_channels == 0 && 456 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 457 ppp_recv_unlock(ppp); 458 break; 459 } 460 ppp_recv_unlock(ppp); 461 } 462 ret = -EAGAIN; 463 if (file->f_flags & O_NONBLOCK) 464 break; 465 ret = -ERESTARTSYS; 466 if (signal_pending(current)) 467 break; 468 schedule(); 469 } 470 set_current_state(TASK_RUNNING); 471 remove_wait_queue(&pf->rwait, &wait); 472 473 if (!skb) 474 goto out; 475 476 ret = -EOVERFLOW; 477 if (skb->len > count) 478 goto outf; 479 ret = -EFAULT; 480 iov.iov_base = buf; 481 iov.iov_len = count; 482 iov_iter_init(&to, READ, &iov, 1, count); 483 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 484 goto outf; 485 ret = skb->len; 486 487 outf: 488 kfree_skb(skb); 489 out: 490 return ret; 491 } 492 493 static ssize_t ppp_write(struct file *file, const char __user *buf, 494 size_t count, loff_t *ppos) 495 { 496 struct ppp_file *pf = file->private_data; 497 struct sk_buff *skb; 498 ssize_t ret; 499 500 if (!pf) 501 return -ENXIO; 502 ret = -ENOMEM; 503 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 504 if (!skb) 505 goto out; 506 skb_reserve(skb, pf->hdrlen); 507 ret = -EFAULT; 508 if (copy_from_user(skb_put(skb, count), buf, count)) { 509 kfree_skb(skb); 510 goto out; 511 } 512 513 skb_queue_tail(&pf->xq, skb); 514 515 switch (pf->kind) { 516 case INTERFACE: 517 ppp_xmit_process(PF_TO_PPP(pf)); 518 break; 519 case CHANNEL: 520 ppp_channel_push(PF_TO_CHANNEL(pf)); 521 break; 522 } 523 524 ret = count; 525 526 out: 527 return ret; 528 } 529 530 /* No kernel lock - fine */ 531 static unsigned int ppp_poll(struct file *file, poll_table *wait) 532 { 533 struct ppp_file *pf = file->private_data; 534 unsigned int mask; 535 536 if (!pf) 537 return 0; 538 poll_wait(file, &pf->rwait, wait); 539 mask = POLLOUT | POLLWRNORM; 540 if (skb_peek(&pf->rq)) 541 mask |= POLLIN | POLLRDNORM; 542 if (pf->dead) 543 mask |= POLLHUP; 544 else if (pf->kind == INTERFACE) { 545 /* see comment in ppp_read */ 546 struct ppp *ppp = PF_TO_PPP(pf); 547 548 ppp_recv_lock(ppp); 549 if (ppp->n_channels == 0 && 550 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 551 mask |= POLLIN | POLLRDNORM; 552 ppp_recv_unlock(ppp); 553 } 554 555 return mask; 556 } 557 558 #ifdef CONFIG_PPP_FILTER 559 static int get_filter(void __user *arg, struct sock_filter **p) 560 { 561 struct sock_fprog uprog; 562 struct sock_filter *code = NULL; 563 int len; 564 565 if (copy_from_user(&uprog, arg, sizeof(uprog))) 566 return -EFAULT; 567 568 if (!uprog.len) { 569 *p = NULL; 570 return 0; 571 } 572 573 len = uprog.len * sizeof(struct sock_filter); 574 code = memdup_user(uprog.filter, len); 575 if (IS_ERR(code)) 576 return PTR_ERR(code); 577 578 *p = code; 579 return uprog.len; 580 } 581 #endif /* CONFIG_PPP_FILTER */ 582 583 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 584 { 585 struct ppp_file *pf; 586 struct ppp *ppp; 587 int err = -EFAULT, val, val2, i; 588 struct ppp_idle idle; 589 struct npioctl npi; 590 int unit, cflags; 591 struct slcompress *vj; 592 void __user *argp = (void __user *)arg; 593 int __user *p = argp; 594 595 mutex_lock(&ppp_mutex); 596 597 pf = file->private_data; 598 if (!pf) { 599 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 600 pf, file, cmd, arg); 601 goto out; 602 } 603 604 if (cmd == PPPIOCDETACH) { 605 /* 606 * We have to be careful here... if the file descriptor 607 * has been dup'd, we could have another process in the 608 * middle of a poll using the same file *, so we had 609 * better not free the interface data structures - 610 * instead we fail the ioctl. Even in this case, we 611 * shut down the interface if we are the owner of it. 612 * Actually, we should get rid of PPPIOCDETACH, userland 613 * (i.e. pppd) could achieve the same effect by closing 614 * this fd and reopening /dev/ppp. 615 */ 616 err = -EINVAL; 617 if (pf->kind == INTERFACE) { 618 ppp = PF_TO_PPP(pf); 619 rtnl_lock(); 620 if (file == ppp->owner) 621 unregister_netdevice(ppp->dev); 622 rtnl_unlock(); 623 } 624 if (atomic_long_read(&file->f_count) < 2) { 625 ppp_release(NULL, file); 626 err = 0; 627 } else 628 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 629 atomic_long_read(&file->f_count)); 630 goto out; 631 } 632 633 if (pf->kind == CHANNEL) { 634 struct channel *pch; 635 struct ppp_channel *chan; 636 637 pch = PF_TO_CHANNEL(pf); 638 639 switch (cmd) { 640 case PPPIOCCONNECT: 641 if (get_user(unit, p)) 642 break; 643 err = ppp_connect_channel(pch, unit); 644 break; 645 646 case PPPIOCDISCONN: 647 err = ppp_disconnect_channel(pch); 648 break; 649 650 default: 651 down_read(&pch->chan_sem); 652 chan = pch->chan; 653 err = -ENOTTY; 654 if (chan && chan->ops->ioctl) 655 err = chan->ops->ioctl(chan, cmd, arg); 656 up_read(&pch->chan_sem); 657 } 658 goto out; 659 } 660 661 if (pf->kind != INTERFACE) { 662 /* can't happen */ 663 pr_err("PPP: not interface or channel??\n"); 664 err = -EINVAL; 665 goto out; 666 } 667 668 ppp = PF_TO_PPP(pf); 669 switch (cmd) { 670 case PPPIOCSMRU: 671 if (get_user(val, p)) 672 break; 673 ppp->mru = val; 674 err = 0; 675 break; 676 677 case PPPIOCSFLAGS: 678 if (get_user(val, p)) 679 break; 680 ppp_lock(ppp); 681 cflags = ppp->flags & ~val; 682 #ifdef CONFIG_PPP_MULTILINK 683 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 684 ppp->nextseq = 0; 685 #endif 686 ppp->flags = val & SC_FLAG_BITS; 687 ppp_unlock(ppp); 688 if (cflags & SC_CCP_OPEN) 689 ppp_ccp_closed(ppp); 690 err = 0; 691 break; 692 693 case PPPIOCGFLAGS: 694 val = ppp->flags | ppp->xstate | ppp->rstate; 695 if (put_user(val, p)) 696 break; 697 err = 0; 698 break; 699 700 case PPPIOCSCOMPRESS: 701 err = ppp_set_compress(ppp, arg); 702 break; 703 704 case PPPIOCGUNIT: 705 if (put_user(ppp->file.index, p)) 706 break; 707 err = 0; 708 break; 709 710 case PPPIOCSDEBUG: 711 if (get_user(val, p)) 712 break; 713 ppp->debug = val; 714 err = 0; 715 break; 716 717 case PPPIOCGDEBUG: 718 if (put_user(ppp->debug, p)) 719 break; 720 err = 0; 721 break; 722 723 case PPPIOCGIDLE: 724 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 725 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 726 if (copy_to_user(argp, &idle, sizeof(idle))) 727 break; 728 err = 0; 729 break; 730 731 case PPPIOCSMAXCID: 732 if (get_user(val, p)) 733 break; 734 val2 = 15; 735 if ((val >> 16) != 0) { 736 val2 = val >> 16; 737 val &= 0xffff; 738 } 739 vj = slhc_init(val2+1, val+1); 740 if (IS_ERR(vj)) { 741 err = PTR_ERR(vj); 742 break; 743 } 744 ppp_lock(ppp); 745 if (ppp->vj) 746 slhc_free(ppp->vj); 747 ppp->vj = vj; 748 ppp_unlock(ppp); 749 err = 0; 750 break; 751 752 case PPPIOCGNPMODE: 753 case PPPIOCSNPMODE: 754 if (copy_from_user(&npi, argp, sizeof(npi))) 755 break; 756 err = proto_to_npindex(npi.protocol); 757 if (err < 0) 758 break; 759 i = err; 760 if (cmd == PPPIOCGNPMODE) { 761 err = -EFAULT; 762 npi.mode = ppp->npmode[i]; 763 if (copy_to_user(argp, &npi, sizeof(npi))) 764 break; 765 } else { 766 ppp->npmode[i] = npi.mode; 767 /* we may be able to transmit more packets now (??) */ 768 netif_wake_queue(ppp->dev); 769 } 770 err = 0; 771 break; 772 773 #ifdef CONFIG_PPP_FILTER 774 case PPPIOCSPASS: 775 { 776 struct sock_filter *code; 777 778 err = get_filter(argp, &code); 779 if (err >= 0) { 780 struct bpf_prog *pass_filter = NULL; 781 struct sock_fprog_kern fprog = { 782 .len = err, 783 .filter = code, 784 }; 785 786 err = 0; 787 if (fprog.filter) 788 err = bpf_prog_create(&pass_filter, &fprog); 789 if (!err) { 790 ppp_lock(ppp); 791 if (ppp->pass_filter) 792 bpf_prog_destroy(ppp->pass_filter); 793 ppp->pass_filter = pass_filter; 794 ppp_unlock(ppp); 795 } 796 kfree(code); 797 } 798 break; 799 } 800 case PPPIOCSACTIVE: 801 { 802 struct sock_filter *code; 803 804 err = get_filter(argp, &code); 805 if (err >= 0) { 806 struct bpf_prog *active_filter = NULL; 807 struct sock_fprog_kern fprog = { 808 .len = err, 809 .filter = code, 810 }; 811 812 err = 0; 813 if (fprog.filter) 814 err = bpf_prog_create(&active_filter, &fprog); 815 if (!err) { 816 ppp_lock(ppp); 817 if (ppp->active_filter) 818 bpf_prog_destroy(ppp->active_filter); 819 ppp->active_filter = active_filter; 820 ppp_unlock(ppp); 821 } 822 kfree(code); 823 } 824 break; 825 } 826 #endif /* CONFIG_PPP_FILTER */ 827 828 #ifdef CONFIG_PPP_MULTILINK 829 case PPPIOCSMRRU: 830 if (get_user(val, p)) 831 break; 832 ppp_recv_lock(ppp); 833 ppp->mrru = val; 834 ppp_recv_unlock(ppp); 835 err = 0; 836 break; 837 #endif /* CONFIG_PPP_MULTILINK */ 838 839 default: 840 err = -ENOTTY; 841 } 842 843 out: 844 mutex_unlock(&ppp_mutex); 845 846 return err; 847 } 848 849 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 850 struct file *file, unsigned int cmd, unsigned long arg) 851 { 852 int unit, err = -EFAULT; 853 struct ppp *ppp; 854 struct channel *chan; 855 struct ppp_net *pn; 856 int __user *p = (int __user *)arg; 857 858 switch (cmd) { 859 case PPPIOCNEWUNIT: 860 /* Create a new ppp unit */ 861 if (get_user(unit, p)) 862 break; 863 err = ppp_create_interface(net, file, &unit); 864 if (err < 0) 865 break; 866 867 err = -EFAULT; 868 if (put_user(unit, p)) 869 break; 870 err = 0; 871 break; 872 873 case PPPIOCATTACH: 874 /* Attach to an existing ppp unit */ 875 if (get_user(unit, p)) 876 break; 877 err = -ENXIO; 878 pn = ppp_pernet(net); 879 mutex_lock(&pn->all_ppp_mutex); 880 ppp = ppp_find_unit(pn, unit); 881 if (ppp) { 882 atomic_inc(&ppp->file.refcnt); 883 file->private_data = &ppp->file; 884 err = 0; 885 } 886 mutex_unlock(&pn->all_ppp_mutex); 887 break; 888 889 case PPPIOCATTCHAN: 890 if (get_user(unit, p)) 891 break; 892 err = -ENXIO; 893 pn = ppp_pernet(net); 894 spin_lock_bh(&pn->all_channels_lock); 895 chan = ppp_find_channel(pn, unit); 896 if (chan) { 897 atomic_inc(&chan->file.refcnt); 898 file->private_data = &chan->file; 899 err = 0; 900 } 901 spin_unlock_bh(&pn->all_channels_lock); 902 break; 903 904 default: 905 err = -ENOTTY; 906 } 907 908 return err; 909 } 910 911 static const struct file_operations ppp_device_fops = { 912 .owner = THIS_MODULE, 913 .read = ppp_read, 914 .write = ppp_write, 915 .poll = ppp_poll, 916 .unlocked_ioctl = ppp_ioctl, 917 .open = ppp_open, 918 .release = ppp_release, 919 .llseek = noop_llseek, 920 }; 921 922 static __net_init int ppp_init_net(struct net *net) 923 { 924 struct ppp_net *pn = net_generic(net, ppp_net_id); 925 926 idr_init(&pn->units_idr); 927 mutex_init(&pn->all_ppp_mutex); 928 929 INIT_LIST_HEAD(&pn->all_channels); 930 INIT_LIST_HEAD(&pn->new_channels); 931 932 spin_lock_init(&pn->all_channels_lock); 933 934 return 0; 935 } 936 937 static __net_exit void ppp_exit_net(struct net *net) 938 { 939 struct ppp_net *pn = net_generic(net, ppp_net_id); 940 struct net_device *dev; 941 struct net_device *aux; 942 struct ppp *ppp; 943 LIST_HEAD(list); 944 int id; 945 946 rtnl_lock(); 947 for_each_netdev_safe(net, dev, aux) { 948 if (dev->netdev_ops == &ppp_netdev_ops) 949 unregister_netdevice_queue(dev, &list); 950 } 951 952 idr_for_each_entry(&pn->units_idr, ppp, id) 953 /* Skip devices already unregistered by previous loop */ 954 if (!net_eq(dev_net(ppp->dev), net)) 955 unregister_netdevice_queue(ppp->dev, &list); 956 957 unregister_netdevice_many(&list); 958 rtnl_unlock(); 959 960 idr_destroy(&pn->units_idr); 961 } 962 963 static struct pernet_operations ppp_net_ops = { 964 .init = ppp_init_net, 965 .exit = ppp_exit_net, 966 .id = &ppp_net_id, 967 .size = sizeof(struct ppp_net), 968 }; 969 970 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 971 { 972 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 973 int ret; 974 975 mutex_lock(&pn->all_ppp_mutex); 976 977 if (unit < 0) { 978 ret = unit_get(&pn->units_idr, ppp); 979 if (ret < 0) 980 goto err; 981 } else { 982 /* Caller asked for a specific unit number. Fail with -EEXIST 983 * if unavailable. For backward compatibility, return -EEXIST 984 * too if idr allocation fails; this makes pppd retry without 985 * requesting a specific unit number. 986 */ 987 if (unit_find(&pn->units_idr, unit)) { 988 ret = -EEXIST; 989 goto err; 990 } 991 ret = unit_set(&pn->units_idr, ppp, unit); 992 if (ret < 0) { 993 /* Rewrite error for backward compatibility */ 994 ret = -EEXIST; 995 goto err; 996 } 997 } 998 ppp->file.index = ret; 999 1000 if (!ifname_is_set) 1001 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1002 1003 ret = register_netdevice(ppp->dev); 1004 if (ret < 0) 1005 goto err_unit; 1006 1007 atomic_inc(&ppp_unit_count); 1008 1009 mutex_unlock(&pn->all_ppp_mutex); 1010 1011 return 0; 1012 1013 err_unit: 1014 unit_put(&pn->units_idr, ppp->file.index); 1015 err: 1016 mutex_unlock(&pn->all_ppp_mutex); 1017 1018 return ret; 1019 } 1020 1021 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1022 const struct ppp_config *conf) 1023 { 1024 struct ppp *ppp = netdev_priv(dev); 1025 int indx; 1026 int err; 1027 1028 ppp->dev = dev; 1029 ppp->ppp_net = src_net; 1030 ppp->mru = PPP_MRU; 1031 ppp->owner = conf->file; 1032 1033 init_ppp_file(&ppp->file, INTERFACE); 1034 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1035 1036 for (indx = 0; indx < NUM_NP; ++indx) 1037 ppp->npmode[indx] = NPMODE_PASS; 1038 INIT_LIST_HEAD(&ppp->channels); 1039 spin_lock_init(&ppp->rlock); 1040 spin_lock_init(&ppp->wlock); 1041 #ifdef CONFIG_PPP_MULTILINK 1042 ppp->minseq = -1; 1043 skb_queue_head_init(&ppp->mrq); 1044 #endif /* CONFIG_PPP_MULTILINK */ 1045 #ifdef CONFIG_PPP_FILTER 1046 ppp->pass_filter = NULL; 1047 ppp->active_filter = NULL; 1048 #endif /* CONFIG_PPP_FILTER */ 1049 1050 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1051 if (err < 0) 1052 return err; 1053 1054 conf->file->private_data = &ppp->file; 1055 1056 return 0; 1057 } 1058 1059 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1060 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1061 }; 1062 1063 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[]) 1064 { 1065 if (!data) 1066 return -EINVAL; 1067 1068 if (!data[IFLA_PPP_DEV_FD]) 1069 return -EINVAL; 1070 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1071 return -EBADF; 1072 1073 return 0; 1074 } 1075 1076 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1077 struct nlattr *tb[], struct nlattr *data[]) 1078 { 1079 struct ppp_config conf = { 1080 .unit = -1, 1081 .ifname_is_set = true, 1082 }; 1083 struct file *file; 1084 int err; 1085 1086 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1087 if (!file) 1088 return -EBADF; 1089 1090 /* rtnl_lock is already held here, but ppp_create_interface() locks 1091 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1092 * possible deadlock due to lock order inversion, at the cost of 1093 * pushing the problem back to userspace. 1094 */ 1095 if (!mutex_trylock(&ppp_mutex)) { 1096 err = -EBUSY; 1097 goto out; 1098 } 1099 1100 if (file->f_op != &ppp_device_fops || file->private_data) { 1101 err = -EBADF; 1102 goto out_unlock; 1103 } 1104 1105 conf.file = file; 1106 err = ppp_dev_configure(src_net, dev, &conf); 1107 1108 out_unlock: 1109 mutex_unlock(&ppp_mutex); 1110 out: 1111 fput(file); 1112 1113 return err; 1114 } 1115 1116 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1117 { 1118 unregister_netdevice_queue(dev, head); 1119 } 1120 1121 static size_t ppp_nl_get_size(const struct net_device *dev) 1122 { 1123 return 0; 1124 } 1125 1126 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1127 { 1128 return 0; 1129 } 1130 1131 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1132 { 1133 struct ppp *ppp = netdev_priv(dev); 1134 1135 return ppp->ppp_net; 1136 } 1137 1138 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1139 .kind = "ppp", 1140 .maxtype = IFLA_PPP_MAX, 1141 .policy = ppp_nl_policy, 1142 .priv_size = sizeof(struct ppp), 1143 .setup = ppp_setup, 1144 .validate = ppp_nl_validate, 1145 .newlink = ppp_nl_newlink, 1146 .dellink = ppp_nl_dellink, 1147 .get_size = ppp_nl_get_size, 1148 .fill_info = ppp_nl_fill_info, 1149 .get_link_net = ppp_nl_get_link_net, 1150 }; 1151 1152 #define PPP_MAJOR 108 1153 1154 /* Called at boot time if ppp is compiled into the kernel, 1155 or at module load time (from init_module) if compiled as a module. */ 1156 static int __init ppp_init(void) 1157 { 1158 int err; 1159 1160 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1161 1162 err = register_pernet_device(&ppp_net_ops); 1163 if (err) { 1164 pr_err("failed to register PPP pernet device (%d)\n", err); 1165 goto out; 1166 } 1167 1168 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1169 if (err) { 1170 pr_err("failed to register PPP device (%d)\n", err); 1171 goto out_net; 1172 } 1173 1174 ppp_class = class_create(THIS_MODULE, "ppp"); 1175 if (IS_ERR(ppp_class)) { 1176 err = PTR_ERR(ppp_class); 1177 goto out_chrdev; 1178 } 1179 1180 err = rtnl_link_register(&ppp_link_ops); 1181 if (err) { 1182 pr_err("failed to register rtnetlink PPP handler\n"); 1183 goto out_class; 1184 } 1185 1186 /* not a big deal if we fail here :-) */ 1187 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1188 1189 return 0; 1190 1191 out_class: 1192 class_destroy(ppp_class); 1193 out_chrdev: 1194 unregister_chrdev(PPP_MAJOR, "ppp"); 1195 out_net: 1196 unregister_pernet_device(&ppp_net_ops); 1197 out: 1198 return err; 1199 } 1200 1201 /* 1202 * Network interface unit routines. 1203 */ 1204 static netdev_tx_t 1205 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1206 { 1207 struct ppp *ppp = netdev_priv(dev); 1208 int npi, proto; 1209 unsigned char *pp; 1210 1211 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1212 if (npi < 0) 1213 goto outf; 1214 1215 /* Drop, accept or reject the packet */ 1216 switch (ppp->npmode[npi]) { 1217 case NPMODE_PASS: 1218 break; 1219 case NPMODE_QUEUE: 1220 /* it would be nice to have a way to tell the network 1221 system to queue this one up for later. */ 1222 goto outf; 1223 case NPMODE_DROP: 1224 case NPMODE_ERROR: 1225 goto outf; 1226 } 1227 1228 /* Put the 2-byte PPP protocol number on the front, 1229 making sure there is room for the address and control fields. */ 1230 if (skb_cow_head(skb, PPP_HDRLEN)) 1231 goto outf; 1232 1233 pp = skb_push(skb, 2); 1234 proto = npindex_to_proto[npi]; 1235 put_unaligned_be16(proto, pp); 1236 1237 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1238 skb_queue_tail(&ppp->file.xq, skb); 1239 ppp_xmit_process(ppp); 1240 return NETDEV_TX_OK; 1241 1242 outf: 1243 kfree_skb(skb); 1244 ++dev->stats.tx_dropped; 1245 return NETDEV_TX_OK; 1246 } 1247 1248 static int 1249 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1250 { 1251 struct ppp *ppp = netdev_priv(dev); 1252 int err = -EFAULT; 1253 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1254 struct ppp_stats stats; 1255 struct ppp_comp_stats cstats; 1256 char *vers; 1257 1258 switch (cmd) { 1259 case SIOCGPPPSTATS: 1260 ppp_get_stats(ppp, &stats); 1261 if (copy_to_user(addr, &stats, sizeof(stats))) 1262 break; 1263 err = 0; 1264 break; 1265 1266 case SIOCGPPPCSTATS: 1267 memset(&cstats, 0, sizeof(cstats)); 1268 if (ppp->xc_state) 1269 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1270 if (ppp->rc_state) 1271 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1272 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1273 break; 1274 err = 0; 1275 break; 1276 1277 case SIOCGPPPVER: 1278 vers = PPP_VERSION; 1279 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1280 break; 1281 err = 0; 1282 break; 1283 1284 default: 1285 err = -EINVAL; 1286 } 1287 1288 return err; 1289 } 1290 1291 static struct rtnl_link_stats64* 1292 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1293 { 1294 struct ppp *ppp = netdev_priv(dev); 1295 1296 ppp_recv_lock(ppp); 1297 stats64->rx_packets = ppp->stats64.rx_packets; 1298 stats64->rx_bytes = ppp->stats64.rx_bytes; 1299 ppp_recv_unlock(ppp); 1300 1301 ppp_xmit_lock(ppp); 1302 stats64->tx_packets = ppp->stats64.tx_packets; 1303 stats64->tx_bytes = ppp->stats64.tx_bytes; 1304 ppp_xmit_unlock(ppp); 1305 1306 stats64->rx_errors = dev->stats.rx_errors; 1307 stats64->tx_errors = dev->stats.tx_errors; 1308 stats64->rx_dropped = dev->stats.rx_dropped; 1309 stats64->tx_dropped = dev->stats.tx_dropped; 1310 stats64->rx_length_errors = dev->stats.rx_length_errors; 1311 1312 return stats64; 1313 } 1314 1315 static struct lock_class_key ppp_tx_busylock; 1316 static struct lock_class_key ppp_qdisc_running_key; 1317 1318 static int ppp_dev_init(struct net_device *dev) 1319 { 1320 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1321 dev->qdisc_running_key = &ppp_qdisc_running_key; 1322 return 0; 1323 } 1324 1325 static void ppp_dev_uninit(struct net_device *dev) 1326 { 1327 struct ppp *ppp = netdev_priv(dev); 1328 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1329 1330 ppp_lock(ppp); 1331 ppp->closing = 1; 1332 ppp_unlock(ppp); 1333 1334 mutex_lock(&pn->all_ppp_mutex); 1335 unit_put(&pn->units_idr, ppp->file.index); 1336 mutex_unlock(&pn->all_ppp_mutex); 1337 1338 ppp->owner = NULL; 1339 1340 ppp->file.dead = 1; 1341 wake_up_interruptible(&ppp->file.rwait); 1342 } 1343 1344 static const struct net_device_ops ppp_netdev_ops = { 1345 .ndo_init = ppp_dev_init, 1346 .ndo_uninit = ppp_dev_uninit, 1347 .ndo_start_xmit = ppp_start_xmit, 1348 .ndo_do_ioctl = ppp_net_ioctl, 1349 .ndo_get_stats64 = ppp_get_stats64, 1350 }; 1351 1352 static struct device_type ppp_type = { 1353 .name = "ppp", 1354 }; 1355 1356 static void ppp_setup(struct net_device *dev) 1357 { 1358 dev->netdev_ops = &ppp_netdev_ops; 1359 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1360 1361 dev->hard_header_len = PPP_HDRLEN; 1362 dev->mtu = PPP_MRU; 1363 dev->addr_len = 0; 1364 dev->tx_queue_len = 3; 1365 dev->type = ARPHRD_PPP; 1366 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1367 netif_keep_dst(dev); 1368 } 1369 1370 /* 1371 * Transmit-side routines. 1372 */ 1373 1374 /* 1375 * Called to do any work queued up on the transmit side 1376 * that can now be done. 1377 */ 1378 static void 1379 ppp_xmit_process(struct ppp *ppp) 1380 { 1381 struct sk_buff *skb; 1382 1383 ppp_xmit_lock(ppp); 1384 if (!ppp->closing) { 1385 ppp_push(ppp); 1386 while (!ppp->xmit_pending && 1387 (skb = skb_dequeue(&ppp->file.xq))) 1388 ppp_send_frame(ppp, skb); 1389 /* If there's no work left to do, tell the core net 1390 code that we can accept some more. */ 1391 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1392 netif_wake_queue(ppp->dev); 1393 else 1394 netif_stop_queue(ppp->dev); 1395 } 1396 ppp_xmit_unlock(ppp); 1397 } 1398 1399 static inline struct sk_buff * 1400 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1401 { 1402 struct sk_buff *new_skb; 1403 int len; 1404 int new_skb_size = ppp->dev->mtu + 1405 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1406 int compressor_skb_size = ppp->dev->mtu + 1407 ppp->xcomp->comp_extra + PPP_HDRLEN; 1408 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1409 if (!new_skb) { 1410 if (net_ratelimit()) 1411 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1412 return NULL; 1413 } 1414 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1415 skb_reserve(new_skb, 1416 ppp->dev->hard_header_len - PPP_HDRLEN); 1417 1418 /* compressor still expects A/C bytes in hdr */ 1419 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1420 new_skb->data, skb->len + 2, 1421 compressor_skb_size); 1422 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1423 consume_skb(skb); 1424 skb = new_skb; 1425 skb_put(skb, len); 1426 skb_pull(skb, 2); /* pull off A/C bytes */ 1427 } else if (len == 0) { 1428 /* didn't compress, or CCP not up yet */ 1429 consume_skb(new_skb); 1430 new_skb = skb; 1431 } else { 1432 /* 1433 * (len < 0) 1434 * MPPE requires that we do not send unencrypted 1435 * frames. The compressor will return -1 if we 1436 * should drop the frame. We cannot simply test 1437 * the compress_proto because MPPE and MPPC share 1438 * the same number. 1439 */ 1440 if (net_ratelimit()) 1441 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1442 kfree_skb(skb); 1443 consume_skb(new_skb); 1444 new_skb = NULL; 1445 } 1446 return new_skb; 1447 } 1448 1449 /* 1450 * Compress and send a frame. 1451 * The caller should have locked the xmit path, 1452 * and xmit_pending should be 0. 1453 */ 1454 static void 1455 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1456 { 1457 int proto = PPP_PROTO(skb); 1458 struct sk_buff *new_skb; 1459 int len; 1460 unsigned char *cp; 1461 1462 if (proto < 0x8000) { 1463 #ifdef CONFIG_PPP_FILTER 1464 /* check if we should pass this packet */ 1465 /* the filter instructions are constructed assuming 1466 a four-byte PPP header on each packet */ 1467 *skb_push(skb, 2) = 1; 1468 if (ppp->pass_filter && 1469 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1470 if (ppp->debug & 1) 1471 netdev_printk(KERN_DEBUG, ppp->dev, 1472 "PPP: outbound frame " 1473 "not passed\n"); 1474 kfree_skb(skb); 1475 return; 1476 } 1477 /* if this packet passes the active filter, record the time */ 1478 if (!(ppp->active_filter && 1479 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1480 ppp->last_xmit = jiffies; 1481 skb_pull(skb, 2); 1482 #else 1483 /* for data packets, record the time */ 1484 ppp->last_xmit = jiffies; 1485 #endif /* CONFIG_PPP_FILTER */ 1486 } 1487 1488 ++ppp->stats64.tx_packets; 1489 ppp->stats64.tx_bytes += skb->len - 2; 1490 1491 switch (proto) { 1492 case PPP_IP: 1493 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1494 break; 1495 /* try to do VJ TCP header compression */ 1496 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1497 GFP_ATOMIC); 1498 if (!new_skb) { 1499 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1500 goto drop; 1501 } 1502 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1503 cp = skb->data + 2; 1504 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1505 new_skb->data + 2, &cp, 1506 !(ppp->flags & SC_NO_TCP_CCID)); 1507 if (cp == skb->data + 2) { 1508 /* didn't compress */ 1509 consume_skb(new_skb); 1510 } else { 1511 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1512 proto = PPP_VJC_COMP; 1513 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1514 } else { 1515 proto = PPP_VJC_UNCOMP; 1516 cp[0] = skb->data[2]; 1517 } 1518 consume_skb(skb); 1519 skb = new_skb; 1520 cp = skb_put(skb, len + 2); 1521 cp[0] = 0; 1522 cp[1] = proto; 1523 } 1524 break; 1525 1526 case PPP_CCP: 1527 /* peek at outbound CCP frames */ 1528 ppp_ccp_peek(ppp, skb, 0); 1529 break; 1530 } 1531 1532 /* try to do packet compression */ 1533 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1534 proto != PPP_LCP && proto != PPP_CCP) { 1535 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1536 if (net_ratelimit()) 1537 netdev_err(ppp->dev, 1538 "ppp: compression required but " 1539 "down - pkt dropped.\n"); 1540 goto drop; 1541 } 1542 skb = pad_compress_skb(ppp, skb); 1543 if (!skb) 1544 goto drop; 1545 } 1546 1547 /* 1548 * If we are waiting for traffic (demand dialling), 1549 * queue it up for pppd to receive. 1550 */ 1551 if (ppp->flags & SC_LOOP_TRAFFIC) { 1552 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1553 goto drop; 1554 skb_queue_tail(&ppp->file.rq, skb); 1555 wake_up_interruptible(&ppp->file.rwait); 1556 return; 1557 } 1558 1559 ppp->xmit_pending = skb; 1560 ppp_push(ppp); 1561 return; 1562 1563 drop: 1564 kfree_skb(skb); 1565 ++ppp->dev->stats.tx_errors; 1566 } 1567 1568 /* 1569 * Try to send the frame in xmit_pending. 1570 * The caller should have the xmit path locked. 1571 */ 1572 static void 1573 ppp_push(struct ppp *ppp) 1574 { 1575 struct list_head *list; 1576 struct channel *pch; 1577 struct sk_buff *skb = ppp->xmit_pending; 1578 1579 if (!skb) 1580 return; 1581 1582 list = &ppp->channels; 1583 if (list_empty(list)) { 1584 /* nowhere to send the packet, just drop it */ 1585 ppp->xmit_pending = NULL; 1586 kfree_skb(skb); 1587 return; 1588 } 1589 1590 if ((ppp->flags & SC_MULTILINK) == 0) { 1591 /* not doing multilink: send it down the first channel */ 1592 list = list->next; 1593 pch = list_entry(list, struct channel, clist); 1594 1595 spin_lock_bh(&pch->downl); 1596 if (pch->chan) { 1597 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1598 ppp->xmit_pending = NULL; 1599 } else { 1600 /* channel got unregistered */ 1601 kfree_skb(skb); 1602 ppp->xmit_pending = NULL; 1603 } 1604 spin_unlock_bh(&pch->downl); 1605 return; 1606 } 1607 1608 #ifdef CONFIG_PPP_MULTILINK 1609 /* Multilink: fragment the packet over as many links 1610 as can take the packet at the moment. */ 1611 if (!ppp_mp_explode(ppp, skb)) 1612 return; 1613 #endif /* CONFIG_PPP_MULTILINK */ 1614 1615 ppp->xmit_pending = NULL; 1616 kfree_skb(skb); 1617 } 1618 1619 #ifdef CONFIG_PPP_MULTILINK 1620 static bool mp_protocol_compress __read_mostly = true; 1621 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1622 MODULE_PARM_DESC(mp_protocol_compress, 1623 "compress protocol id in multilink fragments"); 1624 1625 /* 1626 * Divide a packet to be transmitted into fragments and 1627 * send them out the individual links. 1628 */ 1629 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1630 { 1631 int len, totlen; 1632 int i, bits, hdrlen, mtu; 1633 int flen; 1634 int navail, nfree, nzero; 1635 int nbigger; 1636 int totspeed; 1637 int totfree; 1638 unsigned char *p, *q; 1639 struct list_head *list; 1640 struct channel *pch; 1641 struct sk_buff *frag; 1642 struct ppp_channel *chan; 1643 1644 totspeed = 0; /*total bitrate of the bundle*/ 1645 nfree = 0; /* # channels which have no packet already queued */ 1646 navail = 0; /* total # of usable channels (not deregistered) */ 1647 nzero = 0; /* number of channels with zero speed associated*/ 1648 totfree = 0; /*total # of channels available and 1649 *having no queued packets before 1650 *starting the fragmentation*/ 1651 1652 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1653 i = 0; 1654 list_for_each_entry(pch, &ppp->channels, clist) { 1655 if (pch->chan) { 1656 pch->avail = 1; 1657 navail++; 1658 pch->speed = pch->chan->speed; 1659 } else { 1660 pch->avail = 0; 1661 } 1662 if (pch->avail) { 1663 if (skb_queue_empty(&pch->file.xq) || 1664 !pch->had_frag) { 1665 if (pch->speed == 0) 1666 nzero++; 1667 else 1668 totspeed += pch->speed; 1669 1670 pch->avail = 2; 1671 ++nfree; 1672 ++totfree; 1673 } 1674 if (!pch->had_frag && i < ppp->nxchan) 1675 ppp->nxchan = i; 1676 } 1677 ++i; 1678 } 1679 /* 1680 * Don't start sending this packet unless at least half of 1681 * the channels are free. This gives much better TCP 1682 * performance if we have a lot of channels. 1683 */ 1684 if (nfree == 0 || nfree < navail / 2) 1685 return 0; /* can't take now, leave it in xmit_pending */ 1686 1687 /* Do protocol field compression */ 1688 p = skb->data; 1689 len = skb->len; 1690 if (*p == 0 && mp_protocol_compress) { 1691 ++p; 1692 --len; 1693 } 1694 1695 totlen = len; 1696 nbigger = len % nfree; 1697 1698 /* skip to the channel after the one we last used 1699 and start at that one */ 1700 list = &ppp->channels; 1701 for (i = 0; i < ppp->nxchan; ++i) { 1702 list = list->next; 1703 if (list == &ppp->channels) { 1704 i = 0; 1705 break; 1706 } 1707 } 1708 1709 /* create a fragment for each channel */ 1710 bits = B; 1711 while (len > 0) { 1712 list = list->next; 1713 if (list == &ppp->channels) { 1714 i = 0; 1715 continue; 1716 } 1717 pch = list_entry(list, struct channel, clist); 1718 ++i; 1719 if (!pch->avail) 1720 continue; 1721 1722 /* 1723 * Skip this channel if it has a fragment pending already and 1724 * we haven't given a fragment to all of the free channels. 1725 */ 1726 if (pch->avail == 1) { 1727 if (nfree > 0) 1728 continue; 1729 } else { 1730 pch->avail = 1; 1731 } 1732 1733 /* check the channel's mtu and whether it is still attached. */ 1734 spin_lock_bh(&pch->downl); 1735 if (pch->chan == NULL) { 1736 /* can't use this channel, it's being deregistered */ 1737 if (pch->speed == 0) 1738 nzero--; 1739 else 1740 totspeed -= pch->speed; 1741 1742 spin_unlock_bh(&pch->downl); 1743 pch->avail = 0; 1744 totlen = len; 1745 totfree--; 1746 nfree--; 1747 if (--navail == 0) 1748 break; 1749 continue; 1750 } 1751 1752 /* 1753 *if the channel speed is not set divide 1754 *the packet evenly among the free channels; 1755 *otherwise divide it according to the speed 1756 *of the channel we are going to transmit on 1757 */ 1758 flen = len; 1759 if (nfree > 0) { 1760 if (pch->speed == 0) { 1761 flen = len/nfree; 1762 if (nbigger > 0) { 1763 flen++; 1764 nbigger--; 1765 } 1766 } else { 1767 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1768 ((totspeed*totfree)/pch->speed)) - hdrlen; 1769 if (nbigger > 0) { 1770 flen += ((totfree - nzero)*pch->speed)/totspeed; 1771 nbigger -= ((totfree - nzero)*pch->speed)/ 1772 totspeed; 1773 } 1774 } 1775 nfree--; 1776 } 1777 1778 /* 1779 *check if we are on the last channel or 1780 *we exceded the length of the data to 1781 *fragment 1782 */ 1783 if ((nfree <= 0) || (flen > len)) 1784 flen = len; 1785 /* 1786 *it is not worth to tx on slow channels: 1787 *in that case from the resulting flen according to the 1788 *above formula will be equal or less than zero. 1789 *Skip the channel in this case 1790 */ 1791 if (flen <= 0) { 1792 pch->avail = 2; 1793 spin_unlock_bh(&pch->downl); 1794 continue; 1795 } 1796 1797 /* 1798 * hdrlen includes the 2-byte PPP protocol field, but the 1799 * MTU counts only the payload excluding the protocol field. 1800 * (RFC1661 Section 2) 1801 */ 1802 mtu = pch->chan->mtu - (hdrlen - 2); 1803 if (mtu < 4) 1804 mtu = 4; 1805 if (flen > mtu) 1806 flen = mtu; 1807 if (flen == len) 1808 bits |= E; 1809 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1810 if (!frag) 1811 goto noskb; 1812 q = skb_put(frag, flen + hdrlen); 1813 1814 /* make the MP header */ 1815 put_unaligned_be16(PPP_MP, q); 1816 if (ppp->flags & SC_MP_XSHORTSEQ) { 1817 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1818 q[3] = ppp->nxseq; 1819 } else { 1820 q[2] = bits; 1821 q[3] = ppp->nxseq >> 16; 1822 q[4] = ppp->nxseq >> 8; 1823 q[5] = ppp->nxseq; 1824 } 1825 1826 memcpy(q + hdrlen, p, flen); 1827 1828 /* try to send it down the channel */ 1829 chan = pch->chan; 1830 if (!skb_queue_empty(&pch->file.xq) || 1831 !chan->ops->start_xmit(chan, frag)) 1832 skb_queue_tail(&pch->file.xq, frag); 1833 pch->had_frag = 1; 1834 p += flen; 1835 len -= flen; 1836 ++ppp->nxseq; 1837 bits = 0; 1838 spin_unlock_bh(&pch->downl); 1839 } 1840 ppp->nxchan = i; 1841 1842 return 1; 1843 1844 noskb: 1845 spin_unlock_bh(&pch->downl); 1846 if (ppp->debug & 1) 1847 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1848 ++ppp->dev->stats.tx_errors; 1849 ++ppp->nxseq; 1850 return 1; /* abandon the frame */ 1851 } 1852 #endif /* CONFIG_PPP_MULTILINK */ 1853 1854 /* 1855 * Try to send data out on a channel. 1856 */ 1857 static void 1858 ppp_channel_push(struct channel *pch) 1859 { 1860 struct sk_buff *skb; 1861 struct ppp *ppp; 1862 1863 spin_lock_bh(&pch->downl); 1864 if (pch->chan) { 1865 while (!skb_queue_empty(&pch->file.xq)) { 1866 skb = skb_dequeue(&pch->file.xq); 1867 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1868 /* put the packet back and try again later */ 1869 skb_queue_head(&pch->file.xq, skb); 1870 break; 1871 } 1872 } 1873 } else { 1874 /* channel got deregistered */ 1875 skb_queue_purge(&pch->file.xq); 1876 } 1877 spin_unlock_bh(&pch->downl); 1878 /* see if there is anything from the attached unit to be sent */ 1879 if (skb_queue_empty(&pch->file.xq)) { 1880 read_lock_bh(&pch->upl); 1881 ppp = pch->ppp; 1882 if (ppp) 1883 ppp_xmit_process(ppp); 1884 read_unlock_bh(&pch->upl); 1885 } 1886 } 1887 1888 /* 1889 * Receive-side routines. 1890 */ 1891 1892 struct ppp_mp_skb_parm { 1893 u32 sequence; 1894 u8 BEbits; 1895 }; 1896 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1897 1898 static inline void 1899 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1900 { 1901 ppp_recv_lock(ppp); 1902 if (!ppp->closing) 1903 ppp_receive_frame(ppp, skb, pch); 1904 else 1905 kfree_skb(skb); 1906 ppp_recv_unlock(ppp); 1907 } 1908 1909 void 1910 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1911 { 1912 struct channel *pch = chan->ppp; 1913 int proto; 1914 1915 if (!pch) { 1916 kfree_skb(skb); 1917 return; 1918 } 1919 1920 read_lock_bh(&pch->upl); 1921 if (!pskb_may_pull(skb, 2)) { 1922 kfree_skb(skb); 1923 if (pch->ppp) { 1924 ++pch->ppp->dev->stats.rx_length_errors; 1925 ppp_receive_error(pch->ppp); 1926 } 1927 goto done; 1928 } 1929 1930 proto = PPP_PROTO(skb); 1931 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1932 /* put it on the channel queue */ 1933 skb_queue_tail(&pch->file.rq, skb); 1934 /* drop old frames if queue too long */ 1935 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1936 (skb = skb_dequeue(&pch->file.rq))) 1937 kfree_skb(skb); 1938 wake_up_interruptible(&pch->file.rwait); 1939 } else { 1940 ppp_do_recv(pch->ppp, skb, pch); 1941 } 1942 1943 done: 1944 read_unlock_bh(&pch->upl); 1945 } 1946 1947 /* Put a 0-length skb in the receive queue as an error indication */ 1948 void 1949 ppp_input_error(struct ppp_channel *chan, int code) 1950 { 1951 struct channel *pch = chan->ppp; 1952 struct sk_buff *skb; 1953 1954 if (!pch) 1955 return; 1956 1957 read_lock_bh(&pch->upl); 1958 if (pch->ppp) { 1959 skb = alloc_skb(0, GFP_ATOMIC); 1960 if (skb) { 1961 skb->len = 0; /* probably unnecessary */ 1962 skb->cb[0] = code; 1963 ppp_do_recv(pch->ppp, skb, pch); 1964 } 1965 } 1966 read_unlock_bh(&pch->upl); 1967 } 1968 1969 /* 1970 * We come in here to process a received frame. 1971 * The receive side of the ppp unit is locked. 1972 */ 1973 static void 1974 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1975 { 1976 /* note: a 0-length skb is used as an error indication */ 1977 if (skb->len > 0) { 1978 skb_checksum_complete_unset(skb); 1979 #ifdef CONFIG_PPP_MULTILINK 1980 /* XXX do channel-level decompression here */ 1981 if (PPP_PROTO(skb) == PPP_MP) 1982 ppp_receive_mp_frame(ppp, skb, pch); 1983 else 1984 #endif /* CONFIG_PPP_MULTILINK */ 1985 ppp_receive_nonmp_frame(ppp, skb); 1986 } else { 1987 kfree_skb(skb); 1988 ppp_receive_error(ppp); 1989 } 1990 } 1991 1992 static void 1993 ppp_receive_error(struct ppp *ppp) 1994 { 1995 ++ppp->dev->stats.rx_errors; 1996 if (ppp->vj) 1997 slhc_toss(ppp->vj); 1998 } 1999 2000 static void 2001 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2002 { 2003 struct sk_buff *ns; 2004 int proto, len, npi; 2005 2006 /* 2007 * Decompress the frame, if compressed. 2008 * Note that some decompressors need to see uncompressed frames 2009 * that come in as well as compressed frames. 2010 */ 2011 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2012 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2013 skb = ppp_decompress_frame(ppp, skb); 2014 2015 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2016 goto err; 2017 2018 proto = PPP_PROTO(skb); 2019 switch (proto) { 2020 case PPP_VJC_COMP: 2021 /* decompress VJ compressed packets */ 2022 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2023 goto err; 2024 2025 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2026 /* copy to a new sk_buff with more tailroom */ 2027 ns = dev_alloc_skb(skb->len + 128); 2028 if (!ns) { 2029 netdev_err(ppp->dev, "PPP: no memory " 2030 "(VJ decomp)\n"); 2031 goto err; 2032 } 2033 skb_reserve(ns, 2); 2034 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2035 consume_skb(skb); 2036 skb = ns; 2037 } 2038 else 2039 skb->ip_summed = CHECKSUM_NONE; 2040 2041 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2042 if (len <= 0) { 2043 netdev_printk(KERN_DEBUG, ppp->dev, 2044 "PPP: VJ decompression error\n"); 2045 goto err; 2046 } 2047 len += 2; 2048 if (len > skb->len) 2049 skb_put(skb, len - skb->len); 2050 else if (len < skb->len) 2051 skb_trim(skb, len); 2052 proto = PPP_IP; 2053 break; 2054 2055 case PPP_VJC_UNCOMP: 2056 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2057 goto err; 2058 2059 /* Until we fix the decompressor need to make sure 2060 * data portion is linear. 2061 */ 2062 if (!pskb_may_pull(skb, skb->len)) 2063 goto err; 2064 2065 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2066 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2067 goto err; 2068 } 2069 proto = PPP_IP; 2070 break; 2071 2072 case PPP_CCP: 2073 ppp_ccp_peek(ppp, skb, 1); 2074 break; 2075 } 2076 2077 ++ppp->stats64.rx_packets; 2078 ppp->stats64.rx_bytes += skb->len - 2; 2079 2080 npi = proto_to_npindex(proto); 2081 if (npi < 0) { 2082 /* control or unknown frame - pass it to pppd */ 2083 skb_queue_tail(&ppp->file.rq, skb); 2084 /* limit queue length by dropping old frames */ 2085 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2086 (skb = skb_dequeue(&ppp->file.rq))) 2087 kfree_skb(skb); 2088 /* wake up any process polling or blocking on read */ 2089 wake_up_interruptible(&ppp->file.rwait); 2090 2091 } else { 2092 /* network protocol frame - give it to the kernel */ 2093 2094 #ifdef CONFIG_PPP_FILTER 2095 /* check if the packet passes the pass and active filters */ 2096 /* the filter instructions are constructed assuming 2097 a four-byte PPP header on each packet */ 2098 if (ppp->pass_filter || ppp->active_filter) { 2099 if (skb_unclone(skb, GFP_ATOMIC)) 2100 goto err; 2101 2102 *skb_push(skb, 2) = 0; 2103 if (ppp->pass_filter && 2104 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2105 if (ppp->debug & 1) 2106 netdev_printk(KERN_DEBUG, ppp->dev, 2107 "PPP: inbound frame " 2108 "not passed\n"); 2109 kfree_skb(skb); 2110 return; 2111 } 2112 if (!(ppp->active_filter && 2113 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2114 ppp->last_recv = jiffies; 2115 __skb_pull(skb, 2); 2116 } else 2117 #endif /* CONFIG_PPP_FILTER */ 2118 ppp->last_recv = jiffies; 2119 2120 if ((ppp->dev->flags & IFF_UP) == 0 || 2121 ppp->npmode[npi] != NPMODE_PASS) { 2122 kfree_skb(skb); 2123 } else { 2124 /* chop off protocol */ 2125 skb_pull_rcsum(skb, 2); 2126 skb->dev = ppp->dev; 2127 skb->protocol = htons(npindex_to_ethertype[npi]); 2128 skb_reset_mac_header(skb); 2129 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2130 dev_net(ppp->dev))); 2131 netif_rx(skb); 2132 } 2133 } 2134 return; 2135 2136 err: 2137 kfree_skb(skb); 2138 ppp_receive_error(ppp); 2139 } 2140 2141 static struct sk_buff * 2142 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2143 { 2144 int proto = PPP_PROTO(skb); 2145 struct sk_buff *ns; 2146 int len; 2147 2148 /* Until we fix all the decompressor's need to make sure 2149 * data portion is linear. 2150 */ 2151 if (!pskb_may_pull(skb, skb->len)) 2152 goto err; 2153 2154 if (proto == PPP_COMP) { 2155 int obuff_size; 2156 2157 switch(ppp->rcomp->compress_proto) { 2158 case CI_MPPE: 2159 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2160 break; 2161 default: 2162 obuff_size = ppp->mru + PPP_HDRLEN; 2163 break; 2164 } 2165 2166 ns = dev_alloc_skb(obuff_size); 2167 if (!ns) { 2168 netdev_err(ppp->dev, "ppp_decompress_frame: " 2169 "no memory\n"); 2170 goto err; 2171 } 2172 /* the decompressor still expects the A/C bytes in the hdr */ 2173 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2174 skb->len + 2, ns->data, obuff_size); 2175 if (len < 0) { 2176 /* Pass the compressed frame to pppd as an 2177 error indication. */ 2178 if (len == DECOMP_FATALERROR) 2179 ppp->rstate |= SC_DC_FERROR; 2180 kfree_skb(ns); 2181 goto err; 2182 } 2183 2184 consume_skb(skb); 2185 skb = ns; 2186 skb_put(skb, len); 2187 skb_pull(skb, 2); /* pull off the A/C bytes */ 2188 2189 } else { 2190 /* Uncompressed frame - pass to decompressor so it 2191 can update its dictionary if necessary. */ 2192 if (ppp->rcomp->incomp) 2193 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2194 skb->len + 2); 2195 } 2196 2197 return skb; 2198 2199 err: 2200 ppp->rstate |= SC_DC_ERROR; 2201 ppp_receive_error(ppp); 2202 return skb; 2203 } 2204 2205 #ifdef CONFIG_PPP_MULTILINK 2206 /* 2207 * Receive a multilink frame. 2208 * We put it on the reconstruction queue and then pull off 2209 * as many completed frames as we can. 2210 */ 2211 static void 2212 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2213 { 2214 u32 mask, seq; 2215 struct channel *ch; 2216 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2217 2218 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2219 goto err; /* no good, throw it away */ 2220 2221 /* Decode sequence number and begin/end bits */ 2222 if (ppp->flags & SC_MP_SHORTSEQ) { 2223 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2224 mask = 0xfff; 2225 } else { 2226 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2227 mask = 0xffffff; 2228 } 2229 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2230 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2231 2232 /* 2233 * Do protocol ID decompression on the first fragment of each packet. 2234 */ 2235 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2236 *skb_push(skb, 1) = 0; 2237 2238 /* 2239 * Expand sequence number to 32 bits, making it as close 2240 * as possible to ppp->minseq. 2241 */ 2242 seq |= ppp->minseq & ~mask; 2243 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2244 seq += mask + 1; 2245 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2246 seq -= mask + 1; /* should never happen */ 2247 PPP_MP_CB(skb)->sequence = seq; 2248 pch->lastseq = seq; 2249 2250 /* 2251 * If this packet comes before the next one we were expecting, 2252 * drop it. 2253 */ 2254 if (seq_before(seq, ppp->nextseq)) { 2255 kfree_skb(skb); 2256 ++ppp->dev->stats.rx_dropped; 2257 ppp_receive_error(ppp); 2258 return; 2259 } 2260 2261 /* 2262 * Reevaluate minseq, the minimum over all channels of the 2263 * last sequence number received on each channel. Because of 2264 * the increasing sequence number rule, we know that any fragment 2265 * before `minseq' which hasn't arrived is never going to arrive. 2266 * The list of channels can't change because we have the receive 2267 * side of the ppp unit locked. 2268 */ 2269 list_for_each_entry(ch, &ppp->channels, clist) { 2270 if (seq_before(ch->lastseq, seq)) 2271 seq = ch->lastseq; 2272 } 2273 if (seq_before(ppp->minseq, seq)) 2274 ppp->minseq = seq; 2275 2276 /* Put the fragment on the reconstruction queue */ 2277 ppp_mp_insert(ppp, skb); 2278 2279 /* If the queue is getting long, don't wait any longer for packets 2280 before the start of the queue. */ 2281 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2282 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2283 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2284 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2285 } 2286 2287 /* Pull completed packets off the queue and receive them. */ 2288 while ((skb = ppp_mp_reconstruct(ppp))) { 2289 if (pskb_may_pull(skb, 2)) 2290 ppp_receive_nonmp_frame(ppp, skb); 2291 else { 2292 ++ppp->dev->stats.rx_length_errors; 2293 kfree_skb(skb); 2294 ppp_receive_error(ppp); 2295 } 2296 } 2297 2298 return; 2299 2300 err: 2301 kfree_skb(skb); 2302 ppp_receive_error(ppp); 2303 } 2304 2305 /* 2306 * Insert a fragment on the MP reconstruction queue. 2307 * The queue is ordered by increasing sequence number. 2308 */ 2309 static void 2310 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2311 { 2312 struct sk_buff *p; 2313 struct sk_buff_head *list = &ppp->mrq; 2314 u32 seq = PPP_MP_CB(skb)->sequence; 2315 2316 /* N.B. we don't need to lock the list lock because we have the 2317 ppp unit receive-side lock. */ 2318 skb_queue_walk(list, p) { 2319 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2320 break; 2321 } 2322 __skb_queue_before(list, p, skb); 2323 } 2324 2325 /* 2326 * Reconstruct a packet from the MP fragment queue. 2327 * We go through increasing sequence numbers until we find a 2328 * complete packet, or we get to the sequence number for a fragment 2329 * which hasn't arrived but might still do so. 2330 */ 2331 static struct sk_buff * 2332 ppp_mp_reconstruct(struct ppp *ppp) 2333 { 2334 u32 seq = ppp->nextseq; 2335 u32 minseq = ppp->minseq; 2336 struct sk_buff_head *list = &ppp->mrq; 2337 struct sk_buff *p, *tmp; 2338 struct sk_buff *head, *tail; 2339 struct sk_buff *skb = NULL; 2340 int lost = 0, len = 0; 2341 2342 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2343 return NULL; 2344 head = list->next; 2345 tail = NULL; 2346 skb_queue_walk_safe(list, p, tmp) { 2347 again: 2348 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2349 /* this can't happen, anyway ignore the skb */ 2350 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2351 "seq %u < %u\n", 2352 PPP_MP_CB(p)->sequence, seq); 2353 __skb_unlink(p, list); 2354 kfree_skb(p); 2355 continue; 2356 } 2357 if (PPP_MP_CB(p)->sequence != seq) { 2358 u32 oldseq; 2359 /* Fragment `seq' is missing. If it is after 2360 minseq, it might arrive later, so stop here. */ 2361 if (seq_after(seq, minseq)) 2362 break; 2363 /* Fragment `seq' is lost, keep going. */ 2364 lost = 1; 2365 oldseq = seq; 2366 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2367 minseq + 1: PPP_MP_CB(p)->sequence; 2368 2369 if (ppp->debug & 1) 2370 netdev_printk(KERN_DEBUG, ppp->dev, 2371 "lost frag %u..%u\n", 2372 oldseq, seq-1); 2373 2374 goto again; 2375 } 2376 2377 /* 2378 * At this point we know that all the fragments from 2379 * ppp->nextseq to seq are either present or lost. 2380 * Also, there are no complete packets in the queue 2381 * that have no missing fragments and end before this 2382 * fragment. 2383 */ 2384 2385 /* B bit set indicates this fragment starts a packet */ 2386 if (PPP_MP_CB(p)->BEbits & B) { 2387 head = p; 2388 lost = 0; 2389 len = 0; 2390 } 2391 2392 len += p->len; 2393 2394 /* Got a complete packet yet? */ 2395 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2396 (PPP_MP_CB(head)->BEbits & B)) { 2397 if (len > ppp->mrru + 2) { 2398 ++ppp->dev->stats.rx_length_errors; 2399 netdev_printk(KERN_DEBUG, ppp->dev, 2400 "PPP: reconstructed packet" 2401 " is too long (%d)\n", len); 2402 } else { 2403 tail = p; 2404 break; 2405 } 2406 ppp->nextseq = seq + 1; 2407 } 2408 2409 /* 2410 * If this is the ending fragment of a packet, 2411 * and we haven't found a complete valid packet yet, 2412 * we can discard up to and including this fragment. 2413 */ 2414 if (PPP_MP_CB(p)->BEbits & E) { 2415 struct sk_buff *tmp2; 2416 2417 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2418 if (ppp->debug & 1) 2419 netdev_printk(KERN_DEBUG, ppp->dev, 2420 "discarding frag %u\n", 2421 PPP_MP_CB(p)->sequence); 2422 __skb_unlink(p, list); 2423 kfree_skb(p); 2424 } 2425 head = skb_peek(list); 2426 if (!head) 2427 break; 2428 } 2429 ++seq; 2430 } 2431 2432 /* If we have a complete packet, copy it all into one skb. */ 2433 if (tail != NULL) { 2434 /* If we have discarded any fragments, 2435 signal a receive error. */ 2436 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2437 skb_queue_walk_safe(list, p, tmp) { 2438 if (p == head) 2439 break; 2440 if (ppp->debug & 1) 2441 netdev_printk(KERN_DEBUG, ppp->dev, 2442 "discarding frag %u\n", 2443 PPP_MP_CB(p)->sequence); 2444 __skb_unlink(p, list); 2445 kfree_skb(p); 2446 } 2447 2448 if (ppp->debug & 1) 2449 netdev_printk(KERN_DEBUG, ppp->dev, 2450 " missed pkts %u..%u\n", 2451 ppp->nextseq, 2452 PPP_MP_CB(head)->sequence-1); 2453 ++ppp->dev->stats.rx_dropped; 2454 ppp_receive_error(ppp); 2455 } 2456 2457 skb = head; 2458 if (head != tail) { 2459 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2460 p = skb_queue_next(list, head); 2461 __skb_unlink(skb, list); 2462 skb_queue_walk_from_safe(list, p, tmp) { 2463 __skb_unlink(p, list); 2464 *fragpp = p; 2465 p->next = NULL; 2466 fragpp = &p->next; 2467 2468 skb->len += p->len; 2469 skb->data_len += p->len; 2470 skb->truesize += p->truesize; 2471 2472 if (p == tail) 2473 break; 2474 } 2475 } else { 2476 __skb_unlink(skb, list); 2477 } 2478 2479 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2480 } 2481 2482 return skb; 2483 } 2484 #endif /* CONFIG_PPP_MULTILINK */ 2485 2486 /* 2487 * Channel interface. 2488 */ 2489 2490 /* Create a new, unattached ppp channel. */ 2491 int ppp_register_channel(struct ppp_channel *chan) 2492 { 2493 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2494 } 2495 2496 /* Create a new, unattached ppp channel for specified net. */ 2497 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2498 { 2499 struct channel *pch; 2500 struct ppp_net *pn; 2501 2502 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2503 if (!pch) 2504 return -ENOMEM; 2505 2506 pn = ppp_pernet(net); 2507 2508 pch->ppp = NULL; 2509 pch->chan = chan; 2510 pch->chan_net = get_net(net); 2511 chan->ppp = pch; 2512 init_ppp_file(&pch->file, CHANNEL); 2513 pch->file.hdrlen = chan->hdrlen; 2514 #ifdef CONFIG_PPP_MULTILINK 2515 pch->lastseq = -1; 2516 #endif /* CONFIG_PPP_MULTILINK */ 2517 init_rwsem(&pch->chan_sem); 2518 spin_lock_init(&pch->downl); 2519 rwlock_init(&pch->upl); 2520 2521 spin_lock_bh(&pn->all_channels_lock); 2522 pch->file.index = ++pn->last_channel_index; 2523 list_add(&pch->list, &pn->new_channels); 2524 atomic_inc(&channel_count); 2525 spin_unlock_bh(&pn->all_channels_lock); 2526 2527 return 0; 2528 } 2529 2530 /* 2531 * Return the index of a channel. 2532 */ 2533 int ppp_channel_index(struct ppp_channel *chan) 2534 { 2535 struct channel *pch = chan->ppp; 2536 2537 if (pch) 2538 return pch->file.index; 2539 return -1; 2540 } 2541 2542 /* 2543 * Return the PPP unit number to which a channel is connected. 2544 */ 2545 int ppp_unit_number(struct ppp_channel *chan) 2546 { 2547 struct channel *pch = chan->ppp; 2548 int unit = -1; 2549 2550 if (pch) { 2551 read_lock_bh(&pch->upl); 2552 if (pch->ppp) 2553 unit = pch->ppp->file.index; 2554 read_unlock_bh(&pch->upl); 2555 } 2556 return unit; 2557 } 2558 2559 /* 2560 * Return the PPP device interface name of a channel. 2561 */ 2562 char *ppp_dev_name(struct ppp_channel *chan) 2563 { 2564 struct channel *pch = chan->ppp; 2565 char *name = NULL; 2566 2567 if (pch) { 2568 read_lock_bh(&pch->upl); 2569 if (pch->ppp && pch->ppp->dev) 2570 name = pch->ppp->dev->name; 2571 read_unlock_bh(&pch->upl); 2572 } 2573 return name; 2574 } 2575 2576 2577 /* 2578 * Disconnect a channel from the generic layer. 2579 * This must be called in process context. 2580 */ 2581 void 2582 ppp_unregister_channel(struct ppp_channel *chan) 2583 { 2584 struct channel *pch = chan->ppp; 2585 struct ppp_net *pn; 2586 2587 if (!pch) 2588 return; /* should never happen */ 2589 2590 chan->ppp = NULL; 2591 2592 /* 2593 * This ensures that we have returned from any calls into the 2594 * the channel's start_xmit or ioctl routine before we proceed. 2595 */ 2596 down_write(&pch->chan_sem); 2597 spin_lock_bh(&pch->downl); 2598 pch->chan = NULL; 2599 spin_unlock_bh(&pch->downl); 2600 up_write(&pch->chan_sem); 2601 ppp_disconnect_channel(pch); 2602 2603 pn = ppp_pernet(pch->chan_net); 2604 spin_lock_bh(&pn->all_channels_lock); 2605 list_del(&pch->list); 2606 spin_unlock_bh(&pn->all_channels_lock); 2607 put_net(pch->chan_net); 2608 pch->chan_net = NULL; 2609 2610 pch->file.dead = 1; 2611 wake_up_interruptible(&pch->file.rwait); 2612 if (atomic_dec_and_test(&pch->file.refcnt)) 2613 ppp_destroy_channel(pch); 2614 } 2615 2616 /* 2617 * Callback from a channel when it can accept more to transmit. 2618 * This should be called at BH/softirq level, not interrupt level. 2619 */ 2620 void 2621 ppp_output_wakeup(struct ppp_channel *chan) 2622 { 2623 struct channel *pch = chan->ppp; 2624 2625 if (!pch) 2626 return; 2627 ppp_channel_push(pch); 2628 } 2629 2630 /* 2631 * Compression control. 2632 */ 2633 2634 /* Process the PPPIOCSCOMPRESS ioctl. */ 2635 static int 2636 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2637 { 2638 int err; 2639 struct compressor *cp, *ocomp; 2640 struct ppp_option_data data; 2641 void *state, *ostate; 2642 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2643 2644 err = -EFAULT; 2645 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2646 goto out; 2647 if (data.length > CCP_MAX_OPTION_LENGTH) 2648 goto out; 2649 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2650 goto out; 2651 2652 err = -EINVAL; 2653 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2654 goto out; 2655 2656 cp = try_then_request_module( 2657 find_compressor(ccp_option[0]), 2658 "ppp-compress-%d", ccp_option[0]); 2659 if (!cp) 2660 goto out; 2661 2662 err = -ENOBUFS; 2663 if (data.transmit) { 2664 state = cp->comp_alloc(ccp_option, data.length); 2665 if (state) { 2666 ppp_xmit_lock(ppp); 2667 ppp->xstate &= ~SC_COMP_RUN; 2668 ocomp = ppp->xcomp; 2669 ostate = ppp->xc_state; 2670 ppp->xcomp = cp; 2671 ppp->xc_state = state; 2672 ppp_xmit_unlock(ppp); 2673 if (ostate) { 2674 ocomp->comp_free(ostate); 2675 module_put(ocomp->owner); 2676 } 2677 err = 0; 2678 } else 2679 module_put(cp->owner); 2680 2681 } else { 2682 state = cp->decomp_alloc(ccp_option, data.length); 2683 if (state) { 2684 ppp_recv_lock(ppp); 2685 ppp->rstate &= ~SC_DECOMP_RUN; 2686 ocomp = ppp->rcomp; 2687 ostate = ppp->rc_state; 2688 ppp->rcomp = cp; 2689 ppp->rc_state = state; 2690 ppp_recv_unlock(ppp); 2691 if (ostate) { 2692 ocomp->decomp_free(ostate); 2693 module_put(ocomp->owner); 2694 } 2695 err = 0; 2696 } else 2697 module_put(cp->owner); 2698 } 2699 2700 out: 2701 return err; 2702 } 2703 2704 /* 2705 * Look at a CCP packet and update our state accordingly. 2706 * We assume the caller has the xmit or recv path locked. 2707 */ 2708 static void 2709 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2710 { 2711 unsigned char *dp; 2712 int len; 2713 2714 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2715 return; /* no header */ 2716 dp = skb->data + 2; 2717 2718 switch (CCP_CODE(dp)) { 2719 case CCP_CONFREQ: 2720 2721 /* A ConfReq starts negotiation of compression 2722 * in one direction of transmission, 2723 * and hence brings it down...but which way? 2724 * 2725 * Remember: 2726 * A ConfReq indicates what the sender would like to receive 2727 */ 2728 if(inbound) 2729 /* He is proposing what I should send */ 2730 ppp->xstate &= ~SC_COMP_RUN; 2731 else 2732 /* I am proposing to what he should send */ 2733 ppp->rstate &= ~SC_DECOMP_RUN; 2734 2735 break; 2736 2737 case CCP_TERMREQ: 2738 case CCP_TERMACK: 2739 /* 2740 * CCP is going down, both directions of transmission 2741 */ 2742 ppp->rstate &= ~SC_DECOMP_RUN; 2743 ppp->xstate &= ~SC_COMP_RUN; 2744 break; 2745 2746 case CCP_CONFACK: 2747 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2748 break; 2749 len = CCP_LENGTH(dp); 2750 if (!pskb_may_pull(skb, len + 2)) 2751 return; /* too short */ 2752 dp += CCP_HDRLEN; 2753 len -= CCP_HDRLEN; 2754 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2755 break; 2756 if (inbound) { 2757 /* we will start receiving compressed packets */ 2758 if (!ppp->rc_state) 2759 break; 2760 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2761 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2762 ppp->rstate |= SC_DECOMP_RUN; 2763 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2764 } 2765 } else { 2766 /* we will soon start sending compressed packets */ 2767 if (!ppp->xc_state) 2768 break; 2769 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2770 ppp->file.index, 0, ppp->debug)) 2771 ppp->xstate |= SC_COMP_RUN; 2772 } 2773 break; 2774 2775 case CCP_RESETACK: 2776 /* reset the [de]compressor */ 2777 if ((ppp->flags & SC_CCP_UP) == 0) 2778 break; 2779 if (inbound) { 2780 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2781 ppp->rcomp->decomp_reset(ppp->rc_state); 2782 ppp->rstate &= ~SC_DC_ERROR; 2783 } 2784 } else { 2785 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2786 ppp->xcomp->comp_reset(ppp->xc_state); 2787 } 2788 break; 2789 } 2790 } 2791 2792 /* Free up compression resources. */ 2793 static void 2794 ppp_ccp_closed(struct ppp *ppp) 2795 { 2796 void *xstate, *rstate; 2797 struct compressor *xcomp, *rcomp; 2798 2799 ppp_lock(ppp); 2800 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2801 ppp->xstate = 0; 2802 xcomp = ppp->xcomp; 2803 xstate = ppp->xc_state; 2804 ppp->xc_state = NULL; 2805 ppp->rstate = 0; 2806 rcomp = ppp->rcomp; 2807 rstate = ppp->rc_state; 2808 ppp->rc_state = NULL; 2809 ppp_unlock(ppp); 2810 2811 if (xstate) { 2812 xcomp->comp_free(xstate); 2813 module_put(xcomp->owner); 2814 } 2815 if (rstate) { 2816 rcomp->decomp_free(rstate); 2817 module_put(rcomp->owner); 2818 } 2819 } 2820 2821 /* List of compressors. */ 2822 static LIST_HEAD(compressor_list); 2823 static DEFINE_SPINLOCK(compressor_list_lock); 2824 2825 struct compressor_entry { 2826 struct list_head list; 2827 struct compressor *comp; 2828 }; 2829 2830 static struct compressor_entry * 2831 find_comp_entry(int proto) 2832 { 2833 struct compressor_entry *ce; 2834 2835 list_for_each_entry(ce, &compressor_list, list) { 2836 if (ce->comp->compress_proto == proto) 2837 return ce; 2838 } 2839 return NULL; 2840 } 2841 2842 /* Register a compressor */ 2843 int 2844 ppp_register_compressor(struct compressor *cp) 2845 { 2846 struct compressor_entry *ce; 2847 int ret; 2848 spin_lock(&compressor_list_lock); 2849 ret = -EEXIST; 2850 if (find_comp_entry(cp->compress_proto)) 2851 goto out; 2852 ret = -ENOMEM; 2853 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2854 if (!ce) 2855 goto out; 2856 ret = 0; 2857 ce->comp = cp; 2858 list_add(&ce->list, &compressor_list); 2859 out: 2860 spin_unlock(&compressor_list_lock); 2861 return ret; 2862 } 2863 2864 /* Unregister a compressor */ 2865 void 2866 ppp_unregister_compressor(struct compressor *cp) 2867 { 2868 struct compressor_entry *ce; 2869 2870 spin_lock(&compressor_list_lock); 2871 ce = find_comp_entry(cp->compress_proto); 2872 if (ce && ce->comp == cp) { 2873 list_del(&ce->list); 2874 kfree(ce); 2875 } 2876 spin_unlock(&compressor_list_lock); 2877 } 2878 2879 /* Find a compressor. */ 2880 static struct compressor * 2881 find_compressor(int type) 2882 { 2883 struct compressor_entry *ce; 2884 struct compressor *cp = NULL; 2885 2886 spin_lock(&compressor_list_lock); 2887 ce = find_comp_entry(type); 2888 if (ce) { 2889 cp = ce->comp; 2890 if (!try_module_get(cp->owner)) 2891 cp = NULL; 2892 } 2893 spin_unlock(&compressor_list_lock); 2894 return cp; 2895 } 2896 2897 /* 2898 * Miscelleneous stuff. 2899 */ 2900 2901 static void 2902 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2903 { 2904 struct slcompress *vj = ppp->vj; 2905 2906 memset(st, 0, sizeof(*st)); 2907 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2908 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2909 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2910 st->p.ppp_opackets = ppp->stats64.tx_packets; 2911 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2912 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2913 if (!vj) 2914 return; 2915 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2916 st->vj.vjs_compressed = vj->sls_o_compressed; 2917 st->vj.vjs_searches = vj->sls_o_searches; 2918 st->vj.vjs_misses = vj->sls_o_misses; 2919 st->vj.vjs_errorin = vj->sls_i_error; 2920 st->vj.vjs_tossed = vj->sls_i_tossed; 2921 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2922 st->vj.vjs_compressedin = vj->sls_i_compressed; 2923 } 2924 2925 /* 2926 * Stuff for handling the lists of ppp units and channels 2927 * and for initialization. 2928 */ 2929 2930 /* 2931 * Create a new ppp interface unit. Fails if it can't allocate memory 2932 * or if there is already a unit with the requested number. 2933 * unit == -1 means allocate a new number. 2934 */ 2935 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 2936 { 2937 struct ppp_config conf = { 2938 .file = file, 2939 .unit = *unit, 2940 .ifname_is_set = false, 2941 }; 2942 struct net_device *dev; 2943 struct ppp *ppp; 2944 int err; 2945 2946 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 2947 if (!dev) { 2948 err = -ENOMEM; 2949 goto err; 2950 } 2951 dev_net_set(dev, net); 2952 dev->rtnl_link_ops = &ppp_link_ops; 2953 2954 rtnl_lock(); 2955 2956 err = ppp_dev_configure(net, dev, &conf); 2957 if (err < 0) 2958 goto err_dev; 2959 ppp = netdev_priv(dev); 2960 *unit = ppp->file.index; 2961 2962 rtnl_unlock(); 2963 2964 return 0; 2965 2966 err_dev: 2967 rtnl_unlock(); 2968 free_netdev(dev); 2969 err: 2970 return err; 2971 } 2972 2973 /* 2974 * Initialize a ppp_file structure. 2975 */ 2976 static void 2977 init_ppp_file(struct ppp_file *pf, int kind) 2978 { 2979 pf->kind = kind; 2980 skb_queue_head_init(&pf->xq); 2981 skb_queue_head_init(&pf->rq); 2982 atomic_set(&pf->refcnt, 1); 2983 init_waitqueue_head(&pf->rwait); 2984 } 2985 2986 /* 2987 * Free the memory used by a ppp unit. This is only called once 2988 * there are no channels connected to the unit and no file structs 2989 * that reference the unit. 2990 */ 2991 static void ppp_destroy_interface(struct ppp *ppp) 2992 { 2993 atomic_dec(&ppp_unit_count); 2994 2995 if (!ppp->file.dead || ppp->n_channels) { 2996 /* "can't happen" */ 2997 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2998 "but dead=%d n_channels=%d !\n", 2999 ppp, ppp->file.dead, ppp->n_channels); 3000 return; 3001 } 3002 3003 ppp_ccp_closed(ppp); 3004 if (ppp->vj) { 3005 slhc_free(ppp->vj); 3006 ppp->vj = NULL; 3007 } 3008 skb_queue_purge(&ppp->file.xq); 3009 skb_queue_purge(&ppp->file.rq); 3010 #ifdef CONFIG_PPP_MULTILINK 3011 skb_queue_purge(&ppp->mrq); 3012 #endif /* CONFIG_PPP_MULTILINK */ 3013 #ifdef CONFIG_PPP_FILTER 3014 if (ppp->pass_filter) { 3015 bpf_prog_destroy(ppp->pass_filter); 3016 ppp->pass_filter = NULL; 3017 } 3018 3019 if (ppp->active_filter) { 3020 bpf_prog_destroy(ppp->active_filter); 3021 ppp->active_filter = NULL; 3022 } 3023 #endif /* CONFIG_PPP_FILTER */ 3024 3025 kfree_skb(ppp->xmit_pending); 3026 3027 free_netdev(ppp->dev); 3028 } 3029 3030 /* 3031 * Locate an existing ppp unit. 3032 * The caller should have locked the all_ppp_mutex. 3033 */ 3034 static struct ppp * 3035 ppp_find_unit(struct ppp_net *pn, int unit) 3036 { 3037 return unit_find(&pn->units_idr, unit); 3038 } 3039 3040 /* 3041 * Locate an existing ppp channel. 3042 * The caller should have locked the all_channels_lock. 3043 * First we look in the new_channels list, then in the 3044 * all_channels list. If found in the new_channels list, 3045 * we move it to the all_channels list. This is for speed 3046 * when we have a lot of channels in use. 3047 */ 3048 static struct channel * 3049 ppp_find_channel(struct ppp_net *pn, int unit) 3050 { 3051 struct channel *pch; 3052 3053 list_for_each_entry(pch, &pn->new_channels, list) { 3054 if (pch->file.index == unit) { 3055 list_move(&pch->list, &pn->all_channels); 3056 return pch; 3057 } 3058 } 3059 3060 list_for_each_entry(pch, &pn->all_channels, list) { 3061 if (pch->file.index == unit) 3062 return pch; 3063 } 3064 3065 return NULL; 3066 } 3067 3068 /* 3069 * Connect a PPP channel to a PPP interface unit. 3070 */ 3071 static int 3072 ppp_connect_channel(struct channel *pch, int unit) 3073 { 3074 struct ppp *ppp; 3075 struct ppp_net *pn; 3076 int ret = -ENXIO; 3077 int hdrlen; 3078 3079 pn = ppp_pernet(pch->chan_net); 3080 3081 mutex_lock(&pn->all_ppp_mutex); 3082 ppp = ppp_find_unit(pn, unit); 3083 if (!ppp) 3084 goto out; 3085 write_lock_bh(&pch->upl); 3086 ret = -EINVAL; 3087 if (pch->ppp) 3088 goto outl; 3089 3090 ppp_lock(ppp); 3091 if (pch->file.hdrlen > ppp->file.hdrlen) 3092 ppp->file.hdrlen = pch->file.hdrlen; 3093 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3094 if (hdrlen > ppp->dev->hard_header_len) 3095 ppp->dev->hard_header_len = hdrlen; 3096 list_add_tail(&pch->clist, &ppp->channels); 3097 ++ppp->n_channels; 3098 pch->ppp = ppp; 3099 atomic_inc(&ppp->file.refcnt); 3100 ppp_unlock(ppp); 3101 ret = 0; 3102 3103 outl: 3104 write_unlock_bh(&pch->upl); 3105 out: 3106 mutex_unlock(&pn->all_ppp_mutex); 3107 return ret; 3108 } 3109 3110 /* 3111 * Disconnect a channel from its ppp unit. 3112 */ 3113 static int 3114 ppp_disconnect_channel(struct channel *pch) 3115 { 3116 struct ppp *ppp; 3117 int err = -EINVAL; 3118 3119 write_lock_bh(&pch->upl); 3120 ppp = pch->ppp; 3121 pch->ppp = NULL; 3122 write_unlock_bh(&pch->upl); 3123 if (ppp) { 3124 /* remove it from the ppp unit's list */ 3125 ppp_lock(ppp); 3126 list_del(&pch->clist); 3127 if (--ppp->n_channels == 0) 3128 wake_up_interruptible(&ppp->file.rwait); 3129 ppp_unlock(ppp); 3130 if (atomic_dec_and_test(&ppp->file.refcnt)) 3131 ppp_destroy_interface(ppp); 3132 err = 0; 3133 } 3134 return err; 3135 } 3136 3137 /* 3138 * Free up the resources used by a ppp channel. 3139 */ 3140 static void ppp_destroy_channel(struct channel *pch) 3141 { 3142 atomic_dec(&channel_count); 3143 3144 if (!pch->file.dead) { 3145 /* "can't happen" */ 3146 pr_err("ppp: destroying undead channel %p !\n", pch); 3147 return; 3148 } 3149 skb_queue_purge(&pch->file.xq); 3150 skb_queue_purge(&pch->file.rq); 3151 kfree(pch); 3152 } 3153 3154 static void __exit ppp_cleanup(void) 3155 { 3156 /* should never happen */ 3157 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3158 pr_err("PPP: removing module but units remain!\n"); 3159 rtnl_link_unregister(&ppp_link_ops); 3160 unregister_chrdev(PPP_MAJOR, "ppp"); 3161 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3162 class_destroy(ppp_class); 3163 unregister_pernet_device(&ppp_net_ops); 3164 } 3165 3166 /* 3167 * Units handling. Caller must protect concurrent access 3168 * by holding all_ppp_mutex 3169 */ 3170 3171 /* associate pointer with specified number */ 3172 static int unit_set(struct idr *p, void *ptr, int n) 3173 { 3174 int unit; 3175 3176 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3177 if (unit == -ENOSPC) 3178 unit = -EINVAL; 3179 return unit; 3180 } 3181 3182 /* get new free unit number and associate pointer with it */ 3183 static int unit_get(struct idr *p, void *ptr) 3184 { 3185 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3186 } 3187 3188 /* put unit number back to a pool */ 3189 static void unit_put(struct idr *p, int n) 3190 { 3191 idr_remove(p, n); 3192 } 3193 3194 /* get pointer associated with the number */ 3195 static void *unit_find(struct idr *p, int n) 3196 { 3197 return idr_find(p, n); 3198 } 3199 3200 /* Module/initialization stuff */ 3201 3202 module_init(ppp_init); 3203 module_exit(ppp_cleanup); 3204 3205 EXPORT_SYMBOL(ppp_register_net_channel); 3206 EXPORT_SYMBOL(ppp_register_channel); 3207 EXPORT_SYMBOL(ppp_unregister_channel); 3208 EXPORT_SYMBOL(ppp_channel_index); 3209 EXPORT_SYMBOL(ppp_unit_number); 3210 EXPORT_SYMBOL(ppp_dev_name); 3211 EXPORT_SYMBOL(ppp_input); 3212 EXPORT_SYMBOL(ppp_input_error); 3213 EXPORT_SYMBOL(ppp_output_wakeup); 3214 EXPORT_SYMBOL(ppp_register_compressor); 3215 EXPORT_SYMBOL(ppp_unregister_compressor); 3216 MODULE_LICENSE("GPL"); 3217 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3218 MODULE_ALIAS_RTNL_LINK("ppp"); 3219 MODULE_ALIAS("devname:ppp"); 3220